Can someone tell me how to find the coefficients?

2C2H6 + 7O2 → 4CO2 + 6H2O

Explanation:

First off you find them by balancing the equation ( equal amounts of elements on both sides) So add a two infront of the C2H6. Now you have 4 Carbons and 12 Hydrogens on the left aswell as 2 oxygens.

Now go to the right side and put a 4 infront of CO2 and a 6 infront of H2O. You now have 4 carbons 12 hydrogens and 14 oxygens on the right side.

Finally go back to the let side and place a 7 infront to make the left have 14 oxygens just like in the right. A trick to use is to save the coefficients with only one element till the end so you can do less work in the long run.

But i hope this helped its balanced and down to the smallest whole numbers possible most teachers want whole numbers as the coefficient.

These are tricky at first but once you practice a bit you will be a pro.

the answer to your question is c